scholarly journals Role of Neutron Diffraction in Identifying Stoichiometry and Nonstoichiometry in the Compounds

2020 ◽  
Author(s):  
Som Datta Kaushik ◽  
Anil Kumar Singh
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Neutron Diffraction ◽  
High Temperature Superconductivity ◽  
Research Work ◽  
Point Of View ◽  
X Ray ◽  
The Difference ◽  
Neutron Diffraction And Scattering

In this chapter we introduce stoichiometry and nonstoichiometry from crystal structure point of view along with some examples. We also discussed about the importance of nonstoichiometry in the application oriented research work and their use in the technological applications. We further discuss the ways to identify stoichiometry through various methods. We then introduce neutron diffraction and briefly describe how neutrons and X-ray interacts with matter and the difference in their interaction with matter. We then focus upon its (neutron) usability to identify nonstoichiometry by using some examples available in the literatures. High-temperature superconductivity-based research has seen the importance of neutron diffraction and scattering in identifying the structural modification which leads to superconductivity in the compounds.

The role of π-bonding on the high temperature structure of the double perovskites Ba2CaUO6and BaSrCaUO6

2015 ◽  
Vol 44 (36) ◽  
pp. 16036-16044 ◽  
Author(s):  
Emily Reynolds ◽  
Gordon J. Thorogood ◽  
Maxim Avdeev ◽  
Helen E. A. Brand ◽  
Qinfen Gu ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Neutron Diffraction ◽  
Temperature Structure ◽  
Double Perovskites ◽  
Phase Transition Behavior ◽  
X Ray ◽  
Progressive Loss ◽  
Octahedral Tilting

High temperature synchrotron X-ray and neutron diffraction powder diffraction studies of the uranium perovskites Ba2CaUO6and BaSrCaUO6reveal unusual phase transition behavior associated with the progressive loss of cooperative octahedral tilting.

Crystal structure of magnesium dichloride decahydrate determined by X-ray and neutron diffraction under high pressure

2015 ◽  
Vol 71 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Kazuki Komatsu ◽  
Ayako Shinozaki ◽  
Shinichi Machida ◽  
Takuto Matsubayashi ◽  
Mao Watanabe ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Amorphous State ◽  
Water Molecules ◽  
X Ray ◽  
The Difference ◽  
Diffraction Patterns ◽  
Difference Fourier ◽  
First Time

Magnesium dichloride decahydrate (MgCl2·10H2O) and its deuterated counterpart (MgCl2·10D2O) are identified for the first time byin-situpowder synchrotron X-ray and spallation neutron diffraction. These substances are crystallized from a previously unidentified nanocrystalline compound, which originates from an amorphous state at low temperature. A combination of a recently developed autoindexing procedure and the charge-flipping method reveals that the crystal structure of MgCl2·10H2O consists of an ABCABC... sequence of Mg(H2O)6octahedra. The Cl−anions and remaining water molecules unconnected to the Mg2+cations bind the octahedra, similar to other water-rich magnesium dichloride hydrates. The D positions in MgCl2·10D2O, determined by the difference Fourier methods using the neutron powder diffraction patterns at 2.5 GPa, show the features such as bifurcated hydrogen bonds and tetrahedrally coordinated O atoms, which were not found in other forms of magnesium chloride hydrates.

A NEW HIGH-Tc SUPERCONDUCTOR YBa2Ca2Cu3Ox

1989 ◽  
Vol 03 (16) ◽  
pp. 1233-1236
Author(s):  
A. SHIMA ◽  
T. SHOJI ◽  
M. UKAKU ◽  
Y. WATANABE ◽  
Y. TAZAWA ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
High Temperature Superconductivity ◽  
Liquid Nitrogen Temperature ◽  
X Ray Diffraction ◽  
Oxide Compound ◽  
High Tc ◽  
X Ray ◽  
High Tc Superconductor ◽  
New Superconductor

We report that the high temperature superconductivity observed in a new ceramic Y–Ba–Ca–Cu oxide compound which exhibited the onset of superconductivity clearly at above 90 K and became completely superconductive at liquid nitrogen temperature (77 K). Powder X-ray diffraction analysis showed that the crystal structure of this new superconductor had the same one as a YBa 2 Cu 3 O x.

scholarly journals Pseudo-polymorphism of Halogen Substituted Tetraaza[14]annulene Complexes

2014 ◽  
Vol 70 (a1) ◽  
pp. C1004-C1004
Author(s):  
Shuhei Ichimura ◽  
Masahiro Saeki ◽  
Yoshinori Tamaki ◽  
Kazuo Miyamura
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Single Crystals ◽  
Membered Ring ◽  
Space Group ◽  
X Ray ◽  
Coordination Sites ◽  
The Difference

6,8,15,17-tetramethyldibenzo-5,9,14,18-tetraazacyclotetradecinatonickel (II) (tmtaa) bears strain within its 14-membered ring and is known to adopt saddle-shaped structure. As a consequence, tmtaa has an asymmetric apical coordination sites at both sides of the saddle. Our previous study revealed that the chlorine substituted complex, [Ni(tmtaa-4Cl)] shown in Figure (X = Cl), exhibited pseudo-polymorphism with dichloromethane and chloroform. This behaviour is due to the good affinity between halogen substituents and halomethane solvent. In this study, we grew single crystals of [Ni(tmtaa-4Br)] using various halomethane solvent as crystallization solvents and elucidated the role of the solvents related to the generation of pseudo-polymorprhism. We have succeeded in obtaining two kinds of single crystals 1 and 2 from the same vial container using bromoform. From X-ray structural analysis, 1 and 2 formed twist dimer as with previous report, and are found to include bromoform in their crystal structure. Note that these complexes adopted more distorted saddle-shaped structure than normal tmtaa complexes. The Ni-N4 planes were not planar. The difference of 1 and 2 was the degree of distortion around Ni-N4 plane, and 1 was more distorted than 2. The space group of these complexes were Aba2 and C2/c respectively. The interactions that led to the difference in packing of dimers were CH...π interaction in 1 and π...π interaction in 2.

scholarly journals High-pressure synthesis and crystal structure of the mixed-cation borate Ga4In4B15O33(OH)3

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Mixed Cation ◽  
High Pressure High Temperature ◽  
Pressure Synthesis

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.

X-ray and neutron diffraction study of the defect crystal structure of the as-grown nonstoichiometric phase Y0.715Ca0.285F2.715

2013 ◽  
Vol 58 (4) ◽  
pp. 575-585 ◽  
Author(s):  
N. B. Bolotina ◽  
A. I. Kalyukanov ◽  
T. S. Chernaya ◽  
I. A. Verin ◽  
I. I. Buchinskaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
Nonstoichiometric Phase ◽  
X Ray ◽  
Defect Crystal

scholarly journals Pressure-cooking of explosives—the crystal structure of ε-RDX as determined by X-ray and neutron diffraction

2010 ◽  
Vol 46 (31) ◽  
pp. 5662 ◽  
Author(s):  
David I. A. Millar ◽  
Iain D. H. Oswald ◽  
Christopher Barry ◽  
Duncan J. Francis ◽  
William G. Marshall ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Pressure Cooking ◽  
X Ray

Problematic aspects of the use of penitentiary information in the process of disclosure and investigation of crimes

2020 ◽  
pp. 160-165
Author(s):  
Максим Владимирович Кремлев
Keyword(s):  
Law Enforcement ◽  
Goal Setting ◽  
Point Of View ◽  
Negative Consequences ◽  
The Law ◽  
The Difference

Автор, основываясь на ранее проведенных исследованиях, определяет место и роль пенитенциарной информации в процессе раскрытия и расследования преступлений. Указывается, что пенитенциарная информация превращается в процессуальную и, соответственно, в доказательственную посредством поэтапного прохождения через комплекс действий, облеченных в формы пенитенциарного, оперативно-розыскного и процессуального законодательства. Устанавливаются наиболее уязвимые места с точки зрения содержательного наполнения и процессуального оформления получаемых в рамках режимной деятельности сведений. Таковыми выступают места «сочленения» видов деятельности. Основой для подобного рода высказывания выступает разница в нормативном регулировании, в сменяемости и целеполагании исполнителей, а также их представлении о критериях успешности выполненной работы. В качестве подтверждения выдвинутого тезиса приводится пример из правоохранительной практики использования пенитенциарной информации в процессе доказывания, имеющий негативные последствия. Предлагаются направления совершенствования получения пенитенциарной информации с целью усиления ее доказательственного потенциала. In this article, the author, based on previous research determines the place and role of penitentiary information in the process of disclosure and investigation of crimes. It is specified that penitentiary information turns into procedural and, accordingly, into proofs by means of step-by-step passing through a complex of actions exposed in forms of the penitentiary, operational-search and procedural legislation. The most vulnerable places from the point of view of substantial filling and procedural registration of the data received within regime activity are established. These are the places of “articulation” of activities. It is concluded that the basis for this kind of statement is the difference in regulatory regulation, in the turnover and goal-setting of performers, as well as their representation of the criteria for the success of the work performed. As a confirmation of the proposed thesis, an example from the law enforcement practice of using penitentiary information in the process of proving having negative consequences is given. Directions of improvement of receiving penitentiary information for the purpose of strengthening of its evidentiary potential are offered.

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